There are 15k covid RNA in every ml of sewage coming out of boston right now. Figure 200l a day of sewage per person and that is a lot of covid. I would hold off on eating oysters for a bit. https://www.mwra.com/biobot/biobotdata.htm
why? RNA detected != active virus. e.g. in room temperature, virus can survive the maximum of 5 days (on plastic 3 days, cardboard 24h). It's an impossible vector of transmission.